Transcatheter valve prosthesis

ABSTRACT

A transcatheter atrio-ventricular valve prosthesis for functional replacement of an atrio-ventricular heart valve in a connection channel, the prosthesis comprising a radially expandable tubular body extending along an axis, and a valve arranged within and attached to the tubular body. The tubular body is provided with an outer circumferential groove which is open to the radial outside of the tubular body, whereby the tubular body is separated by the outer circumferential groove into first and second body sections. The tubular body is provided with a first plurality of projections which extend from the first or second body section in an axial direction of the tubular body and each of which has a free end arranged to overlap the outer circumferential groove. An elongate outer member may be disposed at the exterior of the connection channel wall structure at a level of the circumferential groove.

TECHNICAL FIELD

Embodiments generally relate to a transcatheter valve prosthesis,especially a transcatheter atrio-ventricular valve prosthesis.

BACKGROUND

Heart valve diseases are affecting approximately 300.000 peopleworldwide each year. Those diseases translate in abnormal leaflet tissue(excess tissue growth, tissue degradation/rupture, tissuehardening/calcifying), or abnormal tissue position through the cardiaccycle (i.e. annular dilation, ventricular reshaping) leading to adegrading valve function like leakage/blood backflow (valveinsufficiency) or a resistance to blood forward flow (valve stenosis).

Accordingly, a transcatheter valve prosthesis for functional replacementof a heart valve is desirable.

SUMMARY

Various embodiments of the invention provide a transcatheteratrio-ventricular valve prosthesis for functional replacement of anatrio-ventricular heart valve in a connection channel, having acircumferential connection channel wall structure, between the atrialchamber and the ventricular chamber of a heart, comprising a radiallyexpandable tubular body to be disposed in the interior of the connectionchannel and extending along an axis, and a valve arranged within andattached to the tubular body, wherein the tubular body is provided withan outer circumferential groove which is open to the radial outside ofthe tubular body and which defines a groove bottom, whereby the tubularbody is separated by the outer circumferential groove into first andsecond body sections, and wherein the tubular body is provided with afirst plurality of projections which extend from the first or secondbody section in an axial direction of the tubular body and each of whichhas a free end arranged to overlap the outer circumferential groove,further comprising an elongate outer member to be disposed at theexterior of the connection channel wall structure at a level of thecircumferential grove, wherein the outer member can at least partiallyextend around the tubular body with valve tissue of the connectionchannel wall structure being correspondingly circumferentially arrangedbetween the tubular body and the outer member and in such a radialdistance to the axis of the tubular body that the valve tissue of theconnection channel wall structure can be radially forced into the outercircumferential groove so as to be at least partially located radiallybelow the projections.

Various embodiments of the invention further provide a method forimplanting a transcatheter atrio-ventricular valve prosthesis comprisinga tubular body having a longitudinal axis, a circumferential groove anda plurality of projections each having a free end arranged so as topartially overlap the groove, and an elongate outer member, the methodcomprising the steps of positioning the tubular body inside a connectionchannel between an atrial and a ventricular chamber of a heart,positioning the elongate outer member on an outside of the connectionchannel at an axial level of the circumferential groove, and fixatingthe prosthesis relative to the heart by reducing a distance between theelongate outer member and the tubular body so that tissue of theconnection channel is inserted into the groove so as to at leastpartially be radially inside the projections with respect to the axis.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. The drawings are not necessarilyto scale, emphasis instead generally being placed upon illustrating theprinciples of the invention. In the following description, variousembodiments are described with reference to the following drawings, inwhich:

FIG. 1 shows schematically a transcatheter valve prosthesis according toan embodiment located in a connection channel of a human heart,

FIG. 1 a shows a detail of a free end of a projection of the valveprosthesis according to a variation,

FIG. 1 b shows a detail of a free end of a projection of the valveprosthesis according to a variation,

FIG. 2 shows a transcatheter valve prosthesis according to anembodiment,

FIG. 2 a schematically shows extension angles of projections accordingto an embodiment,

FIG. 3 shows schematically a transcatheter valve prosthesis comprisingan elongate outer member according to an embodiment located in aconnection channel of a human heart,

FIG. 4 shows a transcatheter valve prosthesis including a clampingmember according to an embodiment,

FIG. 5 shows the transcatheter valve prosthesis including the clampingmember of FIG. 4 from a different perspective,

FIG. 6 a shows a schematic cross section of a transcatheter valveprosthesis along A-A in FIG. 3,

FIG. 6 b shows a schematic cross section of a transcatheter valveprosthesis along BB in FIG. 3,

FIG. 6 c shows a schematic cross section of a transcatheter valveprosthesis along C-C in FIG. 4 including a clamping member,

FIG. 6 d shows a schematic cross section of a transcatheter valveprosthesis along C-C in FIG. 4 including a clamping member in anotherarrangement than shown in FIG. 6 c.

FIG. 7 schematically shows the interaction of a transcatheter valveprosthesis, heart tissue and an elongate outer member according to anembodiment,

FIG. 8 shows a transcatheter valve prosthesis according to anembodiment,

FIG. 9 shows a tubular body of a transcatheter valve prosthesis,

FIG. 10 schematically shows the transcatheter valve prosthesis includingan outer member, and

FIG. 11 schematically shows the transcatheter valve prosthesis includingan elongate outer member according to a variation.

DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and embodiments inwhich the invention may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice theinvention. Other embodiments may be utilized and structural, logical,and electrical changes may be made without departing from the scope ofthe invention. The various embodiments are not necessarily mutuallyexclusive, as some embodiments can be combined with one or ore otherembodiments to form new embodiments.

With reference to FIGS. 1, 1 a, 1 b and 2, a transcatheteratrio-ventricular valve prosthesis 1 for functional replacement of a(native) atrio-ventricular heart valve 5 in a connection channel 10 thatconnects an atrial heart chamber 15 with a ventricular chamber 20 andcomprising a connection channel wall structure 25 may comprise a tubularbody 30. The tubular body 30 may be disposed in the interior of theconnection channel 10 and extend along an axis 35. The axis 35 may bethe longitudinal axis 35 of the tubular body 30 which may be anelongated body. In the implanted condition, the axis 35 of the tubularbody 30 may be aligned substantially coaxial to an axis of theconnection channel 10. The tubular body 30 may be radially compressibleso as to facilitate approach to and insertion into the connectionchannel 10, e.g. using a catheter or the like, and then be radiallyexpandable so as to closely engage the interior or inner side of theconnection channel wall structure 25, and may comprise an artificialheart valve 40 (e.g. schematically shown in FIG. 6 a) arranged withinthe tubular body 30.

The native atrio-ventricular heart valve 5 (e.g. a mitral valve or atriscupid valve) to be replaced has the generally circumferential wallstructure 25 forming the connection channel 10 or through openingbetween the atrial 15 and ventricular 20 chambers of the heart andincluding a circumferential valve annulus, valve leaflets opening andclosing the connection channel/through opening and closing theconnection channel 10/through opening at a position close to the valveannulus, a generally circumferential cord structure (chordae tendinae)connected between the valve leaflets and generally circumferentialpapillary muscle(s), and said circumferential papillary muscle(s).

The artificial heart valve 40 may be attached to the tubular body 30 andmay be designed to serve as an artificial replacement valve for anatrio-venticular heart valve (for example a mitral and/or a tricuspidvalve). The artificial valve 40 may comprise artificial flaps (e.g.three flaps as schematically shown in e.g. in FIG. 6 a) for functionalreplacement of the native heart valve. The tubular body 30 may beprovided with an outer circumferential groove 45. The outercircumferential groove 45 may be open to the radial outside of thetubular body 30. The circumferential groove 45 may define a groovebottom 46. The outer circumferential groove 45 may define a channel 47which is defined itself by the groove bottom 46 and axially (in axialdirection of the tubular body 30) opposite side walls 48, 49. The groovebottom 46 may separate the tubular body 30 in first and second bodysections 31, 32. The circumferential groove 45 may extend around a wholecircumference of the tubular body 30 or may only extend partially arounda circumference of the tubular body 30. The outer circumferential groove45 may be a continuous that is non-interrupted groove, but may also bean interrupted groove 45 having, for example, two or morecircumferential groove portions 45 provided, for example, on the sameaxial level of the tubular body 30 that are interrupted by areas inwhich no recessed portion, which may provide groove portion, is formed.The circumferential groove 45 may have an axial distance (along axis 35)from the axial ends of the tubular body 30, i.e. the circumferentialgroove 45 may be formed spaced apart in an axial direction from endportions of the tubular body 30.

As shown in FIG. 1, the first body section 31 may be the part of thetubular body 30 that is located above (e.g. proximal from) thecircumferential groove 45, and the second body section 32 may be thepart of the tubular body 30 that is located beneath (e.g. distal from)the circumferential groove 45. Both of the first and second bodysections 31, 32 may have a generally cylindrical shape. According to avariation, the first body section 31 may have a conical shape along theaxis of the tubular body, with its cross-section diameter increasingfrom the groove 45, and the second body section 32 may be generallycylindrical. According to a variation, both of the first and second bodysections 31, 32 may have a conical shape along the axis of the tubularbody, with their respective cross-sectional diameter increasing from thegroove 45. According to variations, the cross sections (along axis 35)of sections 31 and/or 32 may be or contain non circular shapes butelliptical shapes or D-shaped cross sections. In addition, the directionof curvature in the axial profile (seen in a axial section along thetubular body 30) between the groove 45 and the first body section 31and/or between the groove 45 and the second body section 32 may change(from concave curvature of the groove 45 to a convex curvature at thetransition between groove 45 and first and/or second body section 31,32). The axially opposite side walls 48, 49 of the groove 45 may be partof the first and second, respectively, body sections 31, 32 and mayaxially delimit the first and second, respectively, sections 31, 32towards the channel 47 of the groove 45, as it is shown e.g. in FIG. 8.A radial diameter of the first body section 31 (e.g. at an end portionthat is opposite to the second body section 32) of the tubular body 30may be larger than any diameter of the second body section 32. This mayallow to more efficiently fixate the prosthesis 1 in the connectionchannel 10 as the first body section 31 having a larger diameter mayprovide a better hold of the prosthesis 1 in the connection channel 10by providing a friction and/or (mere) form fit (e.g. caused by the firstbody section 31 being located in the atrial chamber 15 and having adiameter larger than a diameter of the connection channel 10).

Further, the valve prosthesis 1 may comprise a first plurality ofprojections 50 and a second plurality of projections 55. The projections50, 55 may extend from the first and second sections 31, 32,respectively, in opposite axial directions, that is they extend, atleast with an extension component or an extension vector, in a directionalong the axis 35 (e.g. the longitudinal axis 35) of the tubular body30. Accordingly, the first projections 50 and the second projections 55extend generally towards each other, whereby they may not extend exactlyor in line towards each other, but with an extension vector. Theprojections 50, 55 may extend substantially parallel to the axis 35 ofthe tubular body 30 or may also extend in a (lateral) angle γ to theaxis 35 of the tubular body 30, wherein the (lateral) angle γ extendstangential to the circumference of the tubular body 30, as it is showne.g. in FIG. 2 a.

The valve prosthesis 1 may comprise one plurality of projections 50, 55only that may extend from the first or second sections 31, 32 in anaxial direction of the tubular body 30 and may overlap thecircumferential groove 45. With reference to e.g. FIGS. 11 a-c, thevalve prosthesis 1 may not comprise any projections 50, 55 and thecircumferential groove 45 may be provided with (e.g. integrally formedon) the tubular body 30.

The projections of the first plurality of projections 50 each may havefree ends 60, and the projections of the second plurality of projections55 each may have free ends 65. The free ends 60, 65 of the first and thesecond plurality of projections 50, 55 may be arranged so as to overlapthe outer circumferential groove 45. That is, the free ends of the firstand second plurality of projections 50, 55 are arranged at an axiallevel of the groove 45 so as to overlap the groove 45. The first andsecond plurality of projections 50, 55 as such may at least partially orcompletely overlap the groove 45 along their extension.

The first 50 and second 55 pluralities of projections may extend in aradial distance radially outwards of the bottom 46 of the groove 45 sothat a hollow (circumferential) chamber 66 is defined between the groovebottom 46 and the first and second plurality of projections 50, 55 inthe channel 47. The opposite side walls 48, 49 may further define thehollow chamber 66 in axial direction of the tubular body 30. Hence, thehollow chamber 66 may be confined radially by the pluralities ofprojections 50, 55 and the groove bottom 46 and axially by oppositesidewalls 48, 49 (e.g. top- and bottom-walls) of the groove 45.

A method of using a transcatheter valve prosthesis 1 may comprisepositioning it in the connection channel wall structure 25 of a heartand then inserting tissue that is adjacent to the circumferential groove45, of the connection channel wall structure 25 into the circumferentialgroove 45 to be placed radially below the first and second plurality ofprojections 50, 55. The tissue can then be held in place in thecircumferential groove 45 by the first 50 and/or second plurality ofprojections 55, which, if, for example, provided with acute or sharpenedends, may penetrate into the tissue which from its position below may bebiased back to its initial radial position. The prosthesis 1 may bepositioned such that its outer circumferential groove 45 is at the levelof the annulus of the circumferential wall structure 25 or adjacentthereto towards the side of the ventricular chamber 20. By the first andsecond plurality of projections 50, 55 keeping the tissue within thegroove 45, the transcatheter valve prosthesis 1 can be positioned andfixated relative to the heart. Further, since the first and secondplurality of projections 50, 55 axially extend towards each other, theprosthesis is further safely and reliably prevented from being axiallypushed out of the connection channel 10 by the pumping activity of theheart. The first 50 and/or the second 55 plurality of projections maykeep the tissue of the connection channel wall structure 25 in thecircumferential groove 45 by perforating it (e.g. transfixing it, e.g.skewering it) and/or by an interference fit. The tissue that is held inthe circumferential groove 45 may also (partially or fully) seal thetranscatheter valve prosthesis 1 against the interior of the connectionchannel 10 so that blood, e.g. pressurized blood, can only flow throughthe tubular body 30 (and the artificial heart valve 40 therein) but cannot bypass the tubular body 30 on its exterior side (i.e. between theexterior of the tubular body 30 and the interior of the connectionchannel wall structure 25). In this respect, the inner and/or outercircumferential surface of the tubular body 30 may additionally beprovided with an impermeable layer, for example in form of a liner 33 b.

The prosthesis 1 may be located in the connection channel 10 so that thecircumferential groove 45 is located on the ventricular side of theannulus of a natural valve, e.g. having a distance from the naturalvalve annulus, i.e. the circumferential groove 45 may be a sub-annularcircumferential groove and/or the prosthesis 1 may be asub-annular-prosthesis 1. The prosthesis 1 may be adapted to be asub-annular prosthesis. That is, the tubular body 30 may have atransverse dimension (also referred to as diameter herein) at an axiallevel (with respect to axis 35) that is smaller than a transversedimension of a natural valve annulus and/or transverse dimension and/oraxial lengths of the tubular body may be suitable so that the first bodysection 31 may be located in an atrial chamber 15 and that the secondbody section 32 may be located in the connection channel 10 with thegroove 45 being located on a ventricular side of the natural valveannulus having a distance to said annulus.

Only one circumferential groove 45 as described above may be provided onthe tubular body 30. However, an elongated prosthesis 1 having two ormore circumferential grooves 45 may be provided, wherein a respectiveset of first and a second plurality of projections 50, 55 as describedabove may be arranged and assigned to the respective one of the two ormore grooves 45. The groove 45 or the respective groove may be formed bythe first and second body sections 31, 32 of the tubular body 30 assuch, wherein the projections 50 and/or 55 may not be involved informing the (respective) groove 45 as such. There may also beembodiments (see further below), in which the projections 50 and/or 55are at least partially in forming the groove 45, for example on the sideof the tubular body 30 that is proximal to the ventricular chamber 20.

The tubular body 30 may comprise or may be a mesh-type body havingelongate mesh or grid elements 33 crossing each other at crossings 34.The mesh elements 33 may be formed from wires comprising steel and/or asuperalloy and/or a shape memory alloy (e.g. nitinol) and/or nickeland/or titanium and/or precious metals (e.g. gold) and/or alloyscomprising the aforementioned. The mesh elements 33 may also compriseother alloys or may be made from organic material, e.g. polymers. Themesh elements 33 may e.g. be made from polyvinyl-chloride and/orpolystyrene and/or polypropylene or another polymer. The tubular body 30may be from a shape-memory material which expands when experiencingusual body temperature. The tubular body 30 may be self-expandable. Thetubular body 30 may also be not self-expandable, but expandable by aballoon or another expansion mechanism. Correspondingly, the tubularbody 30 may be compressible to be insertable via the catheter and maythen be expandable when appropriately positioned with the connectionchannel wall structure 25. The tubular body 30 may comprise theabove-mentioned liner 33 b (c.f. FIG. 6 a) attached to the mesh elements33 made from the same or made from different materials. The liner 33 bmay be disposed on an interior side or art exterior side of the meshelements 33 and/or tubular body 30 and may cover the circumference ofthe tubular body 30 fully or only partially in axial direction 35 and/orin circumferential direction.

The circumferential groove 45 of the tubular body 30 and/or theprojections of the first and/or the second plurality of projections 50,55 may interact with the connection channel wall structure 25 so as tofixate the valve prosthesis 1 with respect to the channel wall structure25 and the connection channel 10. Tissue of the channel wall structure25 may be “caught” in the circumferential groove 45 and be held in placeby the free ends 60, 65 of the first and/or the second plurality ofprojections 50, 55 which may serve as hook elements. The tissue of thechannel wall structure 25 may be perforated by the free ends 60, 65 andthereby held more firmly in the circumferential groove 45 of the tubularbody 30, wherein the tissue may also be held in the groove 45 by meansof an interference and/or clamping fit between the projections 50 and/or55 (or part thereof) and the tissue of the connection channel wallstructure 25. In order to allow the first and/or second plurality ofprojections 50, 55 to penetrate the tissue of the circumferentialconnection channel wall structure 25, which has been forced into thegroove, the free ends of a plurality or of each of the first 50 and/orsecond 55 pluralities of projections may be an acute or sharpened end.The projections of the first and/or second plurality of projections 50,55 each or some thereof may be pins.

With further reference to FIG. 1 b, the free ends 60, 65 of the firstand/or the second plurality of projections 50, 55 may be conical ends 70so as to be able to perforate tissue of the connection channel wallstructure 25. According to a variation, the free ends 60, 65 of thefirst and/or the second plurality of projections 50, 55 may also beblunt. The free ends 60, 65 and/or the first and/or second plurality ofprojections 50, 55 may be pin-shaped.

Some or all of the free ends 60, 65 of the projections 55, 60 maycomprise barbs or hooks 71 as shown in FIG. 1 a. The hooks 71 may serveto perforate tissue of the connection channel wall structure 25 andprevent the tissue from slipping off the free end 60, 65. Thereby tissuethat is perforated by barbs or hooks 71 disposed on a free end 60, 65 isunable to slip from the free end 55, 65 resulting in tissue from theheart valve connection channel wall structure 25 being caught even morereliably in the circumferential groove 45. Some or all of the free ends60, 65 may be blunt or may have conical ends 70 or comprise barbs orhooks 71. The first 50 or second 55 plurality of projections maycomprise different types of free ends 60, 65 according to the anatomicalconditions, but may also comprise the same type of free ends 60, 65.

The free ends 60, 65 and/or the first 50 and second pluralities 55 ofprojections may be arranged in different axial and/or radial positionsand orientations with respect to each other. With reference to FIGS. 1and 6 a, each projection of the first plurality of projections 50 mayhave the same circumferential angular distance a (that is an angulardistance between two radial directions extending from longitudinal axis35 of the tubular body 30) from each other, i.e. the projections 50 maybe equally circumferentially spaced. However, the projections of thefirst plurality of projections 50 may also have different angulardistances a from each other, i.e. be not spaced evenly around acircumference of the tubular body. Although not shown in FIGS. 6 a-c,similarly, each projection of the second plurality of projections 55 mayhave the same angular distance from each other, i.e. be spaced equallyaround a circumference of the tubular body 30. However, the projectionsof the second plurality of projections 55 may also have differentcircumferential angular distances a from each other, i.e. be not spacedevenly around a circumference of the tubular body.

The first plurality of projections 50 may be arranged with respect tothe second plurality of projections 55 on the tubular body 30 in a waythat each projection of the first plurality of projections 50 issubstantially on the same radial level (that is the same radius, e.g.R2) as a projection of the second plurality of projections 55 (as it isshown e.g. in FIGS. 1 and 3). On the other hand, each projection of thefirst plurality of projections 50 may be arranged on a different radiusthan a projection of the second plurality of projections 55, wherein thefirst plurality of projections 50 may each be on a same radius, andwherein the second plurality of projections 55 may each be on a sameradius.

With, for example, reference to FIGS. 1 and 3, the first plurality ofprojections 50 and the second plurality of projections 55 may extend soas to be aligned or coaxial to each other. The first plurality ofprojections 50 may also not be aligned with the second plurality ofprojections 55, wherein the first plurality of projections 50 maythemselves extend substantially parallel to each other or may not, andwherein the second plurality of projections 55 may themselves extendsubstantially parallel to each other or may not.

With, for example, reference to FIGS. 2 and 4, the first and secondplurality of projections 50, 55 may be arranged in circumferentialdirection in an alternating manner, wherein for example each firstprojection 50 is circumferentially between two second projections 55(and the other way round). There may also be other appropriatecircumferential arrangement patterns for the first and second pluralityof projections 50, 55, wherein, for example, sets of first projections50, of for example one, two, three, four, or more first projections 50,are arranged between sets of second projections 55, of for example one,two, three, four or more second projections 50.

The number of the projections of the first plurality of projections 50and the number of projections of the second plurality of projections 55may be, for example, in a range of three to five, or eight to ten,fifteen to twenty, thirty to hundred or more or may be any other number.The first plurality of projections 50 may comprise the same number ofprojections or another number of projections as the second plurality ofprojections 55 or vice versa.

The projections of the first plurality of projections 50 and/or theprojections of the second plurality of projections 55 may extend fromthe tubular body 30 from positions, where mesh elements 33 of thetubular body 30 are crossing with each other at the crossings 34. Thismay improve the mechanical stability of the interconnection of thetubular body 30 with the projections 50, 55. The projections 50, 55 maye.g. be welded, soldered and/or braided to the tubular body 35. They mayalso be sutured, bonded or glued to the tubular body 35. As analternative or additionally, the projections 50, 55 may also bemonolithically integrally formed with the tubular body 30. That is, withreference to e.g. FIGS. 9 a and 9 b, the projections 50,55 (or any oneor bath of the pluralities of projections) may be formed by meshelements 33 that are not connected to another mesh element 33 at acrossing 34 but are projecting from the tubular body 30 (e.g. caused bybending the mesh element 33) in a radial and/or axial direction withrespect to longitudinal axis 35 so as to form a projection 50, 55.Further, projections 50, 55 (e.g. monolithically integrally formed bymesh elements 33 or provided separately and connected with the tubularbody 30) may form the circumferential groove 45 by projecting radiallyand axially from the tubular body 30 with respect to its longitudinalaxis 35. Accordingly, by facing away from the tubular body 30, theprojections may define a circumferential groove 45 on the tubular body30. The circumferential groove 45 may also be further defined by agenerally conical or similar shape of a body section (e.g. first bodysection 31 and/or second body section 32) of the tubular body 30 thathas a cross-sectional diameter that is increasing from the groove 45 ina direction of longitudinal axis 35. As seen e.g. in FIGS. 9 a and 9 b,the generally conical shape of a body section 31, 32 may accordinglyinteract with the projections 50, 55 which are projecting from thetubular body 30 so as to further define the circumferential groove 45.FIG. 9 a shows projections 50, 55 that define a circumferential groove45 by projecting first in a substantially radial direction relative tothe longitudinal axis 35 and then in a substantially parallel directionto the longitudinal axis 35 when seen from the point from which theprojections extend from tubular body 30. FIG. 9 b shows projections 50,55 that extend generally rectilinearly to define the circumferentialgroove 45. The projections 50, 55 may be made from the same materialsthat were described above with reference to the tubular body 30, e.g.super alloys, e.g. shape memory alloys (like nitinol) or steel ortitanium (or alloys comprising titanium) or organic material likepolymers, or the projections may be made from different material ormaterials.

As can be seen e.g. from FIG. 8, all or some projections of the firstplurality of projections 50 and/or all or some projections of the secondplurality of projections 55 may be extending in (e.g. along) asubstantially straight line or in a straight line, i.e. they may notcomprise any longitudinal curvature from the point from which theyextend from the tubular body 30 to their respective free end 60, 65,i.e. they may extend rectilinearly. They may, however, neverthelesscomprise barbs or hooks 71 and/or may be pin-shaped. The first pluralityof projections 50 may extend from substantially the same axial level(relating to the axial direction of the tubular body 30) from thetubular body 30 (e.g. shown in FIGS. 1 to 3) or may extend fromdifferent axial levels from the tubular body 30. Correspondingly, thesecond plurality of projections 55 may extend from substantially thesame axial level (relating to the axial direction of the tubular body30) from the tubular body 30 (e.g. shown in FIGS. 1 to 3) or may extendfrom different axial levels from the tubular body 30. The axialextension of the first plurality of projections 50 (axial distance(along axis 35 of tubular body 30) between base of projection on thetubular body and free end of projection) and/or of the second pluralityof projections 55 may be substantially the same or may be different, andthe extension or length of the first plurality of projections 50 and/orof the second plurality of projections 55 (distance between basis of theprojection 50, 55 on the tubular body 30 and the free end 60, 65 of theprojection 50, 55) may be the same or may be different.

In addition to the first and second plurality of projections 50, 55 thetubular body 30 may be provided with any other type of projection and/orcollar.

The first 50 and the second plurality 55 of projections may extend fromthe first 31 and the second 32 body sections, respectively, from areasthat are adjacent to or are bordering the radial outer circumference ofthe circumferential groove 45. The first 50 and the second plurality 55of projections may extend from the opposite side walls 48, 49 laterallydefining the groove 45.

Referring to FIG. 2, the free ends 60 of the first 50 plurality ofprojections may be axially spaced from the free ends 65 of the second 55plurality of projections by an axial distance W2 in a direction of theaxis 35 of the tubular body 30. The free ends 60 of first plurality ofprojections 50 may be arranged on a same axial level or on differentaxial levels, and the free ends 65 of the second plurality ofprojections 55 may be arranged on a same axial level or on differentaxial levels.

In case a transcatheter valve prosthesis 1 comprises one plurality ofprojections 50, 55, the axial distance W2 may define a distance of oneor more or all of the free ends 60, 65 of the (one) plurality ofprojections 50, 55 to a side all 48, 49, that is opposite to therespective body section 31, 32 the plurality of projections extendingfrom, of the circumferential groove 45.

The projections of the first plurality of projections 50 may axiallyoverlap with the projections of the second plurality 55 of projectionswith each other (not shown), wherein there may be defined an axialoverlapping-distance between the free ends 60 of the first plurality ofprojections 50 and the free ends 65 of the second plurality ofprojections 55. Some free ends 60 of the first plurality of projections50 may be axially spaced from corresponding free ends 65 of the secondplurality of projections 55, while other free ends 60 and 65 may bearranged so as to axially overlap each other.

With reference, for example, to FIG. 2 a, the projections 50, 55 (each)may extend in a manner so as to be radially and inwardly inclined by anangle β, thereby obliquely extending into the outer circumferentialgroove 45. The angle β defining the radial and inward inclination of theprojections 50, 55 with respect to the axis 35 of the tubular body 30may be an acute angle, for example in a range of equal or smaller than45° or equal or smaller than 30°, or equal or smaller than 15°. Only apart or number of the first projections 50 and/or only a part or numberof the second projections 55 may radially and inwardly inclined as abovedescribed.

FIG. 6 a, which corresponds to the cross section along A-A shown in FIG.3, illustrates the interaction of heart valve tissue of the connectionchannel wall structure 25 and the first plurality of projections 50 (across-section transverse the axis 35 and through the second plurality ofprojections 55 would result in a similar depiction as shown in FIG. 6a). The first plurality of projections 50 can be seen perforating tissueof the connection channel wall structure 25 to thereby more reliablyprevent it from retracting from the tubular body 30 of the prosthesis 1,which results in the prosthesis 1 being held more firmly in its intendedplace.

With further reference to FIG. 3 and FIG. 6 b, the transcatheteratrio-ventricular valve prosthesis 1 may further comprise an elongateouter member 75. The elongate outer member 75 may be disposed at theexterior of the connection channel wall structure 25 (i.e. e.g. in theventricular chamber 20) at an axial level (e.g. with respect to axis 35)of the circumferential groove 45 of the tubular body 30. The elongateouter member 75 may extend at least partially around, for examplecompletely and continuously circumferentially around, the tubular body30 and may be handled e.g. using a catheter member 90 that is shownschematically in FIG. 6 b. A radial distance R5 between the longitudinalaxis 35 and the elongate outer member 75 may be reducible or reduced sothat the valve tissue of the connection channel wall structure 25 can becorrespondingly at least partially forced into the outer circumferentialgroove 45 so as to be at least partially be located radially below thefirst and second plurality of projections 50, 55. The radial distance R5may be reducible or reduced so that it is smaller than a radial distanceR4 that is defined between the longitudinal axis 35 of the tubular body30 and the free ends 60, 65 of the projections 50, 55 (the free ends 60,65 are not visible in the cross section shown in FIG. 6 b, but they areindicated by crosses in FIG. 6 b). This means, that the elongate outermember 75 may be positioned inside the circumference defined by thefirst and the second plurality of projections 50, 55 so that tissue ofthe connection channel wall structure 25 is or can be located in thecircumferential groove 45 between the groove bottom 46 and the first andsecond projections 50, 55, wherein the elongate outer member 75 itselfmay be located inside the groove 45 between the groove bottom 46 and thefirst and second plurality of projections 50, 55. However, the elongateouter member 75 may also be arranged to force tissue of the connectionchannel wall structure 25 into the circumferential groove 45 but toremain outside the groove (i.e. R5 may be larger than R4 as it is shownin FIG. 6 b). The catheter member 90, or an other, for example similarlystructured catheter device, may be used to handle and position theelongate outer member 75 around an exterior of the circumferentialconnection channel wall structure 25.

With further reference to FIGS. 6 b and 7, the catheter member 90 maycomprise a connecting means 91, for example a cutting and clampingmeans, that can be used to connect free ends of the elongate member 75,for example to cut the elongate outer member 75 and clamp two ends of ittogether, so that the elongate member 75 may remain permanently aroundthe tubular body 30 and thereby forms a component of the prosthesis 1.However, the elongate outer member 75 may also merely be aninterventional tool, for example as a component of catheter member, andmay only be used to radially force the tissue of the connection channelwall structure 25 into the outer groove 45, and may then be withdrawn orremoved from the heart. When the elongate member 75 remains permanentlypositioned around an outer side of the connection channel wall structure25, it may permanently apply a radial and inwardly directed force to thetissue of the connection channel wall structure 25 towards the groove45.

With reference to FIGS. 1, 3, 6 b and 7 there may be several ways inwhich heart tissue of the connection channel wall structure 25 isfixated, held and/or caught in the circumferential groove 45. The tissuemay be perforated by the free ends 60, 65 of the first and/or the secondplurality of projections 50, 55 e.g. via the acute ends 70 and/or thebarbs or hooks 71. The tissue may also be held in the circumferentialgroove 45 by an interference fit between the projections 50, 55. Thetissue may also be held in the circumferential groove 45 by the elongateouter member 75. The elongate outer member 75 may be used to force thetissue into the groove 45 either temporarily (e.g. as a method stepduring a heart treatment) or permanently (for example, if the cuttingand clamping means 91 is used to cut elongate outer member 75 and toconnect its two ends together permanently while it is extending aroundthe exterior of the connection channel wall structure 25 as shown inFIG. 7). The tissue of the connection channel wall structure 25 may alsobe held in the circumferential groove 45 by a combination of two or moreof the above described means and effects.

In all embodiments, the elongate outer member 75 may have across-sectional diameter D1 (see e.g. FIG. 6 b) that is smaller than awidth W1 of the outer circumferential groove 45 (illustrated e.g. inFIG. 2). The elongate member 75 may also have a cross-sectional diameterD1 that is smaller than the gap W2 between the free ends 60, 65 of thefirst and the second plurality of projections 50, 55. The elongatemember 75 may have a cross-sectional diameter D1 that is larger thanwidth W2 but smaller than width W1. The elongate member 75 may have across-sectional diameter D1 that is larger than width W2 and/or widthW1. The elongate member 75 may be a wire or a band, and may have acircular cross section or a rectangular cross section. The elongatemember 75 may also have a triangular cross section or a cross sectiondefining any other shape. The elongate member 75 may be made from anymaterial that has been described with reference to the mesh elements 33or a combination of those materials or other material(s). For example,the elongate member may be made from steel, a titanium alloy or a shapememory alloy such as nitinol.

Further, a length of the projections 50 and/or 55 may be related to thewidth W1 of the circumferential groove 45. In this respect, the ratio ofa distance between the free ends 60, 65 of the first and secondpluralities of projections 50, 55 (or, if only one plurality ofprojections 50, 55 is provided, a distance of the free ends 60, 65 ofthat plurality of projections 50, 55 to the sidewall 48, 49 of thecircumferential groove 45 that is with respect to axis 35 opposite tothe projections 50, 55) to the width W1 of the circumferential groove 45may have a maximum value of 0.5 or 0.4 or 0.3 or 0.2 or 0.1. Accordinglythe hollow chamber 66 may be defined between the projections 50, 55 andthe groove bottom 46. The width W1 of the circumferential groove 45 maybe defined between the sidewalls 48, 49 of the groove 45 and/or betweena point from which a projection 50, 55 of the first and/or secondplurality of projections 50, 55 extends from the tubular body 30 and asidewall 48, 49 that is located on an opposite side of the groove (45)and/or between a point from which a projection from the first pluralityof projections 50 extends and a point from which a projection form thesecond plurality of projections 55 extends.

With reference to FIGS. 4 and 5 (for improved clarity and understanding,the transcatheter valve prosthesis 1 is shown without artificial valve40), the transcatheter valve prosthesis 1 may also comprise a clampingmember 80. The clamping member 80 may comprise a tubular structurehaving a longitudinal axis that may be arranged so as to extend in thecircumferential groove 45 in a circumferential direction of the tubularbody 30. The clamping member 80 may be located in the circumferentialgroove 45 so as to be located (for example at least partly) radiallyinwards of the first and second pluralities 50, 55 of projections. Theclamping member 80 may be in contact with the groove bottom 46 of thecircumferential groove 45. The clamping member 80 may extend around awhole circumference of the tubular body 30 or only partially around thetubular body 30, as shown e.g. in FIGS. 4 and 5. The clamping member 80may extend e.g. around an angle of 10 to 30 degrees or any other anglein the circumferential groove 45. The clamping member 80 may also extendaround the whole circumference of groove 45, e.g. around 360 degrees.The clamping member 80 may have a cross-sectional diameter D2 transverseto its longitudinal axis. The cross-sectional diameter D2 may beselectively changeable to a larger or smaller diameter D2, i.e. theclamping member 80 may be compressible (so as to be insertable via acatheter) and/or expandable (for example, re-expandable after beingcompressed) in a radial direction of its diameter D2, whereby the innerand outer circumferences of the clamping member are correspondinglydecreased/expanded and expanded/decreased, respectively, in a radialdirection of the tubular body 30 towards the first and/or the secondplurality of projections 50, 55. The cross sectional diameter D2 of theclamping member 80 may be smaller than the cross sectional diameter(radius R1 is shown e.g. in FIG. 6 a) of the tubular body 30. Theclamping member 80 may be provided in order to clamp heart tissue thatis located inside the circumferential groove 45 outwards in a directionfrom the axis 35 towards the pluralities of projections 50, 55.

With reference to FIG. 6 d, the clamping member 80 may also be or formpart of the above described elongate outer member 75, wherein theclamping member 80 may then be arranged and/or guided and/or positioned(in a radially compressed condition) at the circumferential outer sideof the connection channel wall structure 25 to completely or partlyextend around the connection channel wall structure 25 at an axial (withrespect to the axis 35 of the tubular body 30) level, and may then beradially expanded (in a direction of the diameter D2 of the clampingmember 80), whereby its inner diameter in a radial direction of thetubular member 30 then correspondingly decreases to thereby force thetissue of the inwardly arranged connection channel wall structure 25(which is then arranged inwards of the clamping member 80) radially intothe groove 45. That is, the clamping member may be located between theprojections 50, 55 and tissue of the connection channel wall structure25, that may be pressed into the groove 45 by an elastic force exertedby the clamping member 80 on the tissue of the connection channel wallstructure 25 and a corresponding reactive force that may be exerted bythe clamping member 80 on the projections 50, 55. The forces that mayact upon the tissue of the connection channel wall structure 25 exertedby the clamping member 80 and the groove 45 (e.g. the groove bottom 46)are schematically indicated by arrows 85 b. The elongate outer member 75and/or the clamping member 80 (which may be the same member) may serveto anchor the prosthesis 1 and to seal the native heart leaflets againstthe prosthesis 1 against blood flow. Further, immobilization of thenative leaflets by the prosthesis 1 as described herein (e.g. comprisinga clamping member 80 and/or elongate member 75) may favour the ingrowthof heart (e.g. leaflet) tissue into the prosthesis (e.g. circumferentialgroove 45) and thereby further improve fixation of the prosthesis 1relative to the heart and/or sealing against blood flow as the ingrowntissue may additionally or alternatively seal against blood flow on anoutside of the tubular body 30.

FIG. 6 c shows a schematic cross sectional view of the tubular body 30and the clamping member 80 similar to the cross section CC in FIG. 4,however additionally showing heart tissue of the connection channel wallstructure 25 that is not shown in FIG. 4. In FIG. 6 c, the positions ofthe first or second pluralities of projections 50, 55 are indicated bydots 50, 55. As can be seen from FIG. 6 c, the heart tissue of theconnection channel wall structure 25 is located inside thecircumferential groove 45 radially between the groove bottom 46 of thetubular body 30 and a diameter that is defined by the free ends 60, 65of the first and/or the second plurality of projections 50, 55. It canbe seen from FIG. 6 c that the clamping member 80 is elasticallystrained by the tissue of the connection channel wall structure 25 andin turn exerts a force that presses the tissue of the connection channelwall structure 25 against the free ends 60, 65. Arrows 85 indicate theforces that are caused by the clamping member 80 and that act upon thetissue of the connection channel wall structure 25 in the groove 45.

With reference e.g. to FIGS. 6 c and 6 d, which show only one clampingmember 80, there may also e.g. be two or more clamping members 80arranged in the groove 45 which are arranged in parallel to each otherand/or which are arranged sequentially in a circumferential direction,with for example a circumferential distance therebetween or abuttingeach other, of the tubular body 30. For example, there may be twoclamping members 80 abutting each other and a third clamping member 80that has an angular distance from the two clamping members 80 that areabutting each other may also be arranged in the groove 45. Clampingmembers 80 may e.g. be positioned on diametrically opposite sides of thegroove 45. These two or more (e.g. 3 to 5) clamping members 80 may allhave the same cross-sectional diameter D2 or may each have differentcross-sectional diameters. The clamping members 80 may all have the samelongitudinal length or may have different longitudinal lengths (e.g. ina circumferential direction of tubular body 30). Clamping members 80 maybe designed and arranged so that the tubular body 30 is firmly held inplace according to the specific tissue structure and conditions of theconnection channel wall structure 25 of a specific heart (e.g. of apatient). They may e.g. be specifically chosen and arranged by anoperator or surgeon to firmly hold the tubular body 30 in placeaccording to local conditions. The respective clamping member 80 mayhave an other shape than a tubular, such as a block-shape, a cubic-shapeor a ball-shape.

The force acting on the tissue of the connection channel wall structure25 may be increased when the clamping member 80 is used together withthe elongate outer member 75 thereby further improving the connectionbetween the transcatheter valve prosthesis 1 and the connection channelwall structure 25. In this case, an elastic force origination form theclamping member 80 pointing from the axis 35 outwards and a forceoriginating from the elongate outer member 75 pointing inwards to theaxis 35 act upon tissue of the connection channel wall structure 25,thereby holding the prosthesis 1 firmly in its intended position in theconnection channel 10. However, the valve prosthesis 1 may be usedwithout the clamping member 80 and the elongate outer member 75 as well(i.e. by itself) or together with only one (anyone) of them. Aprosthesis 1 not comprising a plurality of projections 50, 55 may befixated by clamping member 80 and/or elongate outer member 75, e.g. whenthe elongate outer member 75 and/or the clamping member 80 are/isgenerally rigid, e.g. when comprising or being an inflatable balloonthat is filled with a substance giving it rigidity caused by a pressureor by a curing of that substance. That substance can cure with a limitedamount of time, with the injection of an additional agent (eg areticulating agent), with application of heat or energy. It can be PMMA(Poly Methyl Methacrylate), different epoxies, polyurethane, a blend ofpolyurethane silicone. It can be strengthened with the addition ofreinforcement fibers (eg Kevlar, carbon).

Clamping member 80 may be made from a mesh-type structure as shown inFIGS. 4 and 5 and may comprise an inner lumen. The mesh may be made frommetal or organic material or other material. The mesh of clamping member80 may be made e.g. from iron, nickel, aluminium and/or titanium and/oralloys of these metals and other elements. The mesh may be made e.g.from steel (e.g. spring steel), and/or an superalloy and/or shape memoryalloy (such as e.g. nitinol), Ti 6Al 4V, and/or a precious metal likegold or any combination of those and/or other materials. The mesh ofclamping member 80 may also be made from polymers, e.g. frompolypropylene or polyvinylchloride, Polyethylene or Nylon. Of course,the mesh may also be made from combinations of these materials, i.e. itmay be made from two or more different materials. In one embodiment, theclamping member can be an expandable stent-graft made with a steel ornitinol stent covered with a Dacron or ePTFE graft. The mesh of clampingmember may also or additionally comprise any material that has beendescribed with reference to the mesh elements 33 of the tubular body 30and/or with reference to the elongate member 75 and the clamping member80 may be designed and a material for it may be chosen so as to create ahigh elastic force to press the tissue of the connection channel wallstructure 25 against the projections 50, 55. Clamping member 80 may alsobe provided with hooks or barbs to create an attachment to tubular body30.

Clamping member 80 and/or elongate outer member 75 may also comprise aninflatable inner member (not shown). The inflatable inner member may bedisposed in an inner lumen of the clamping member 80 and may be inflatedso as to increase diameter D2 of clamping member 80 thereby pressingtissue of the connection channel wall structure 25 against theprojections 50, 55 (either from an inner side if the clamping member 80is arranged in the hollow chamber 66 or from an outer side if theclamping member 80 is initially arranged at an outer side of theconnection channel wall structure 25). The inner member may be inflatedby the operator using a tubing and fluid from an external pressuresource, e.g. a syringe, a fluid bottle or a pump located outside thebody. The clamping member 80 may also be an inflatable member 80 thatpresses tissue of the connection channel wall structure 25 against theprojections 55, 55 when inflated. Both the inflatable inner member andthe inflatable member 80 may be made from a fluid tight, pressureresistant material, e.g. a material or polymer as described above withreference to the clamping member 80 or any other suitable material. Withreference to e.g. FIG. 1I, the inflatable member may comprise anaperture 76 (e.g. a valve, e.g. an opening) through which a substance(e.g. via a delivery tube (not shown)) may be delivered into theinflatable member or out of the inflatable member. The aperture 76 maybe selectively permitting the transmission of a substance (i.e. have an“open-state”) or may be blocking the transmission of a substance (i.e.have a “closed-state”). The aperture 76 may serve to fill the inflatablemember or to un-fill (e.g. to empty) the inflatable member in order tochange a cross-sectional diameter of the inflatable member. The clampingmember 80 and/or the elongate outer member 75 may be made of an elasticmaterial (e.g. a polymer and/or a metal) and/or may be filled with ancompressible (e.g. elastical) substance (e.g. a gas and/or a foammaterial and/or a hydrogel) to provide a damping/cushioningfunctionality. A substance for filling the inflatable member may be agas, a liquid or any other substance and/or may be a substance thatchanges its phase (e.g. gas, liquid, solid) when in the inflatablemember (the substance may e.g. change from liquid phase to a generallysolid phase). The substance may be a substance that is capable of curingand/or hardening when disposed in the inflatable member so as to providea generally rigid clamping member 80 and/or elongate outer member 75.

Clamping member 80 may apply a force to the opposite side walls 48, 49of groove 45, for instance upon radial expansion relatively to itslongitudinal axis. This force may increase or decrease the distancebetween body sections 31 and 32 and/or the distance between axial ends(with respect to axis 35) of the tubular body 30. Tubular body 30 may bemade to be elastic (e.g. comprising a mesh structure and/or an elasticmaterial). The force exerted by clamping member 80 may also result in aexpansion or reduction of a perimeter of the groove bottom 46 along acircumference of groove 45 and/or in an expansion or reduction ofdiameter R1 of the tubular body 30 at an axial height (with respect toaxis 35) of groove 45 respectively. The clamping member 80 and/or theelongate outer member 75 (which may be the same member or may beseparate members) may also not produce a force in a radial directionand/or a longitudinal direction of the tubular body 30 with respect toits longitudinal axis 35. Accordingly, the clamping member 80 and/or theelongate outer member 75 may act as a displacement member by displacingtissue of the connection channel 10 without exerting a clamping force tothe tubular body 30 but by providing a mere interference fit between thecircumferential wall structure 25 of the connection channel 10, theclamping member 80 and/or the tubular body 30 in addition or asalternative to e.g. tissue being pierced by projections of the first 50and/or second plurality of projections 55.

The clamping member 80 and/or elongate outer member 75 may be locatedonly partially radially inwards of the first 50 and/or second 55plurality of projections and may be located so as to be pierced byanyone or both pluralities of projections so as to be held relative tothe tubular body 30. The elongate outer member 75 and/or clamping member80 may be pierced by only one plurality of projections 50, 55 and theother plurality of projections may not pierce the clamping member80/elongate outer member 75 (or, the other plurality of projections maynot be provided in case of a prosthesis 1 only comprising one (a)plurality of projections (on one side of the groove 45)). The pluralityof projections 50 and/or 55 may be piercing the clamping member 80 sothat the respective free ends 60, 65 of the projections 50, 55 endinside the clamping member 80 or so that the free ends 60, 65 of therespective projections 50, 55 are penetrating through the clampingmember 80 and exit from the clamping member so that the respective freeends 60, 65 may be located outside the clamping member 80.

With reference to FIG. 10 b, the elongate outer member 75 and/or theclamping member 80 may also be provided in the groove 45 radiallyinwards of the projections 50, 55 so that the elongate outer member 75and/or the clamping member 80 is not pierced by the projections 50, 55.The elongate outer member 75/clamping member 80 may be held by a mereinterference fit or a frictional/interference fit between the groove 45,the tissue of the connection channel wall structure 25 and/orprojections 50, 55 in the groove 45 (e.g. when inflated, e.g. whenexpanded). Further, as schematically shown in FIG. 10 b, the elongateouter member 75/clamping member 80 may have a cross sectional shape thatis substantially elliptical or has any other shape, such as atriangular, rectangular or polygonal shape. The substantially ellipticalshape of the elongate outer member 75/clamping member 80 that is shownin FIG. 10 b may be caused by the design of the elongate outer member75/clamping member 80, e.g. when it is provided with a tubular structurehaving a substantially elliptical shape (e.g. when expanded), or it maybe caused by anisotropic forces acting upon elongate outer member75/clamping member 80 caused e.g. by the projections 50, 55, the tissueof the circumferential wall structure 25 and/or groove 45. That is, theelongate outer member 75/clamping member 80 may have a substantiallyround cross section when no external forces act upon it and may beassuming a different shape (e.g. elliptical), when implanted (and, e.g.expanded).

With reference to e.g. FIG. 10 c, an expandable and/or reducibleelongate outer member 75 (e.g. clamping member 80) may have a diameterD2 that may be larger than width W1 of circumferential groove 45 whenexpanded so that the elongate outer member 75 may extend out of thegroove 45 and may occupy a space between the circumferential wallstructure 25 and tissue forming a heart chamber (e.g. the ventricularchamber 20 and/or atrial chamber 15), i.e. the elongate outer member 75may form a shape arranged between (e.g. abutting) the connection channelwall structure 25 and tissue/muscles of a heart chamber wall (e.g. ofventricular chamber 20) when expanded (e.g. fully expanded).Accordingly, the elongate outer member 75 may be located (e.g.partially, e.g. a part thereof) radially outside (with respect to axis35) the circumferential groove 45 and may extend parallel to axis 35along one or both body sections 31, 32 (e.g. along second body section32) of tubular body 30 while being (e.g. partially, e.g. a part ofelongate outer member 75) located radially outside groove (45).Accordingly, the elongate member 75 may comprise an angularly shaped(e.g. substantially describing an angle of about 90°) cross section witha first angular leg 75 a that may be extending with respect to axis 35generally radially into the groove 45, and a second angular leg 75 bthat may be extending generally parallel to axis 35 of the tubular body30 on an outside of the tubular body 30 (e.g. along first body section31 and/or second body section 32). That is, the elongate outer member 75(e.g. second angular leg 75 b thereof) may be disposed between the first31 and/or second 32 body section and tissue/muscle forming a wall of aheart chamber such as the ventricular chamber 20 and/or atrial chamber15. While in FIG. 10 a-c the elongate outer member 75/clamping member 80is only shown on one side of the prosthesis 1, it may also extend fullyor partially (as shown e.g. in FIG. 11 a-d) around the prosthesis 1(e.g. the circumferential groove 45). The elongate outer member75/clamping member 80 may comprise free ends 77, 78 (e.g. two free ends77, 78) in a direction of a central-longitudinal axis that may benon-connected and/or not abutting each other, i.e. spaced away from eachother. The free ends 77, 78 may have an angular distance from each other(e.g. in the groove 45, e.g. when inflated in the groove 45) defined byan angle of e.g. less than 180′, less than 90°, less than 45° or lessthan 10° with respect to axis 35. The aperture 76 may be provided on oneof these free ends 77, 78 or a an aperture 76 may be provided on each ofthe free ends 77, 78. When the elongate outer member 75/clamping member80 only extends partially around circumferential groove 45 andaccordingly comprises free ends, it may have a rigidity caused by asubstance, e.g. by a curing substance (that may be cured).

Accordingly, the clamping member 80/elongate outer member 75 (e.g. whenit comprises an elastic and/or compressible material, e.g. as describedabove) may serve to dampen movement of the heart (e.g. caused by thebeating heart, e.g. pulse) by acting as a dampening and/or cushioningmember between the heart (e.g. a heart chamber) and the prosthesis 1(e.g. tubular body 30) to further improve the fixation of the prosthesis1 relative in the heart by reducing forces caused by the beating heartacting on the prosthesis 1 by dampening these forces. Accordingly, theclamping member 80/elongate outer member 75 may absorb movements (e.g.of the ventricular wall (e.g. of the papillary muscle of the ventricularchamber 20) to avoid pulsation of the prosthesis 1. The clamping member80 may serve to maintain a distance of the prosthesis 1 from tissue ofthe heart (e.g. from a wall of the ventricular chamber 20 and/or theatrial chamber 15) and thereby improve placement and/or fixation of theprosthesis 1. Accordingly, the elongate outer member 75 and/or theclamping member 80 may serve as a damping member and/or a spacer member.The clamping member 80 and/or the elongate outer member 75 and hence,the groove 45, may be arranged on a side of the ventricular chamber whenseen from the annulus of the natural valve having a distance from theannulus.

The shape of a cross section of tubular body 30 across its longitudinalaxis (e.g. axis 35) may be modified. Catheter member 90 may comprise orprovide a piercing component that can be positioned through theconnection channel wall structure 25 (e.g. from an outside of connectionchannel wall structure 25) and through the tubular body 30 insubstantially diametrically positions relatively to an axial (withrespect to axis 35) cross section. The piercing component may be hollowand enable placement of an anchor on connection channel wall structure25 at the distal position of a diameter of the connection channel wallstructure 25 relatively to catheter member 90. Said anchor may beattached to a longitudinal end of a longitudinal component (e.g. atether) which in turn may be provided with a second anchor on its otherlongitudinal end. The second anchor may be placed by the piercingcomponent upon retrieval of the piercing component form the connectionchannel wall structure 25 at the proximal end (relatively to cathetermember 90) of said diameter on connection channel wall structure 25. Thelength of said longitudinal component can be designed to be undertension from forces acting on the longitudinal component induced by thefirst and second anchors, so as to create a deformation of tubular body30 in a substantially elliptical shape, e.g. the longitudinal componentmay be shorter than a diameter of the tubular body 30 when no externalforces act upon tubular body 30. The longitudinal component may beplaced across an inner lumen of tubular body 30 in a position where itdoes not interfere with the function of valve 40, e.g. be geometricallyspaced away from the valve 40. It may also be small enough to avoidsignificant interference with blood flow through tubular body 30, e.g.may have a radius or a diameter ranging from 100 μm to 1000 μm.

All embodiments of the transcatheter valve prosthesis 1 may comprisepositioning and/or orientation devices to facilitate relative and/orabsolute positioning of the tubular body 30 and/or the elongate outermember 75 and/or the clamping member 80. These devices may includepassive markers that are fixedly attached to the tubular body 30 and/orthe elongate outer member 75 and/or the clamping member 80. The passivemarkers may be made from materials different from the materials of thetubular body 30 and/or the elongate outer member 75 and/or the clampingmember 80 in order to improve contrast during medical imaging, e.g.using magnetic resonance or X-ray based imaging techniques. The passivemarkers may e.g., be made of highly radio-opaque materials therebyallowing to precisely acquire the relative and/or absolute position ofthe components of the transcatheter valve prosthesis 1 with respect tothe body. The passive markers may each have an asymmetrical shape so asto allow identifying the absolute and/or relative position andorientation and thereby the position and orientation of the tubular body30 and/or the elongate outer member 75 and/or the clamping member 80.The passive markers may also have an identical shape and may be arrangedin a certain configuration relative to each other to allow recognitionof the orientation. The circumferential groove 45 of the tubular body 30and/or the tubular body 30 and/or the elongate outer member 75 and/orthe clamping member 80 may have passive markers fixedly attached tofacilitate positioning them relative to each other using imagingtechniques, e.g. passive markers made of highly radio-opaque materialswhen imaging techniques based on electro-magnetic radiation (e.g. X-rayimaging) are used. In addition and/or as an alternative, thecircumferential groove 45 and/or other parts/components of the tubularbody 30 and/or the elongate outer member 75 and/or the clamping member80 may be made from radio-opaque materials.

A method for using a transcatheter prosthesis 1 as described above maycomprise:

Placing the transcatheter valve prosthesis 1 within an atrio-ventricularvalve, e.g. in a mitral or a tricuspid valve of a human or animal heart,via an insertion catheter. The transcatheter valve prosthesis 1 may e.g.be placed in a connection channel wall structure 25 between aventricular chamber 20 and an atrial chamber 15 as shown in FIG. 1.

To place transcatheter valve prosthesis 1 within the heart valve, thefollowing approaches may be applied: 1) an arterial retrograde approachentering the heart cavity over the aorta, 2) through a venous access andthrough a puncture through the inter atrial septum (trans-septalapproach), 3) over a puncture through the apex of the heart(trans-apical approach), 4) over a puncture through the atrial wall fromoutside the heart, 5) arterial access (e.g. the femoral artery through apuncture in the groin) or 6) any other approach known to a skilledperson. The approach to the valve is facilitated as the tubular body 30is radially compressible and extendable and may e.g. be folded andstuffed in a catheter during approach and may be unfolded/extended whenbeing within the circumferential connection channel wall structure 25.The transcatheter valve prosthesis 1 may include the clamping member 80or the clamping member 80 may be inserted separately via one of thementioned approaches (e.g. using a catheter) so as to be placed in thecircumferential groove 45 of the tubular body 30 when the tubular body30 is located in the connection channel wall structure 25. The clampingmember 80 may be compressible and expandable.

Fixating the transcatheter valve prosthesis 1 in the heart relative tothe valve.

For functional replacement of a heart valve, the transcatheter valveprosthesis 1 is fixated relative to the connection channel wallstructure 25 and sealed against blood flow on the exterior of thetranscatheter valve prosthesis 1 in the connection channel wallstructure 25. To achieve this, tissue of the connection channel wallstructure 25 adjacent to the circumferential groove 45 may be forced orplaced inside the circumferential groove 45 to engage radially below thefirst 50 and second 55 pluralities of projections whereby the tissue isprevented from slipping out of the groove 45 by the first 50 and/orsecond 55 plurality of projections, wherein the free ends 60, 65 of thefirst 50 and/or second plurality 55 of projections may penetrate thetissue. The tissue of the connection channel wall structure 25 may be(completely) perforated, or example partially perforated, by theprojections 50, 55 and may thereby be prevented from slipping out of thecircumferential groove 45. The clamping member 80 or two or moreclamping members 80 may be provided in the circumferential groove 45 toactively press tissue of the connection channel wall structure 25against the free ends 60,65 so as to interlock the tissue with the freeends 60, 65. This results in the transcatheter valve prosthesis 1 beingheld in place more firmly and sealed against blood flow between theexterior of the tubular body 30 and the connection channel wallstructure 25.

To place tissue in the circumferential groove 45 of the tubular body 30,a method for using a transcatheter valve prosthesis 1 may comprise usingan elongate outer member 75 to radially and inwardly force tissue of theconnection channel wall structure 25 into the circumferential groove 45(which may or may not comprise a clamping member 80). With reference toFIG. 3, the elongate outer member 75 may be disposed at an exterior ofthe connection channel wall structure 25 at a level of thecircumferential groove 45. Then, with further reference to FIG. 6 b, adistance R5 between the elongate outer member 75 and the axis 35 of thetubular body is reduced (that means that also a distance between thebottom 46 of the circumferential groove 45 of the tubular body 30 andthe elongate outer member 75 is reduced) so as to force tissue of theconnection channel wall structure 25 into the circumferential groove 45to fixate the tissue in the circumferential groove 45. The elongateouter member 75 may be handled via a catheter member 90 and an approachas described in relation to the transcatheter valve prosthesis 1 or anyother approach may be used in order to bring the elongate outer member75 in the vicinity of the connection channel wall structure 25. When thetissue of the connection channel wall structure 25 is held in thecircumferential groove 45 by the projections 50, 55, the elongatedmember 75 (and the catheter member 90) may be removed from the heart or,as shown illustratively in FIG. 7, the connecting means 91 of thecatheter member 90 may be used in order to permanently connect two(free) ends of the elongate outer member 75 together and cut the ends sothat elongate outer member 75 remains permanently on the exterior of aconnection channel wall structure 25 on a level of the circumferentialgroove 45 of the tubular body 30 so as to additionally hold tissue ofthe connection channel wall structure 25 in the circumferential groove45.

A method for using the transcatheter atrio-ventricular prosthesis 1 mayresult in the transcatheter valve prosthesis 1 being fixated to theconnection channel wall structure 25 and being firmly held in place viathe tissue that is held in the circumferential groove 45 by the freeends 60, 65, optionally supported by the clamping member 80 and/or thepermanently disposed elongate outer member 75.

Features of the transcather atrio-venticular valve prosthesis 1 andmethod steps involving the prosthesis that have been described herein(description and/or figures and/or claims) referring to a transcatheratrio-venticular valve prosthesis 1 comprising first 50 and second 55pluralities of projections also apply to a transcatheteratrio-venticular valve prosthesis 1 comprising one plurality ofprojections (50, 55) and vice versa. In particular, features describedin the application (description, claims, figures) to further define theprojections of the first and second plurality of projections are alsoapplicable to only the first plurality of projections if, for example,the valve prosthesis only comprises the first plurality of projections(as it is, for example, the case in claim 1). All features herein aredisclosed to be interchangeable between all embodiments of thetranscather atrio-venticular valve prosthesis 1.

1. A transcatheter atrio-ventricular valve prosthesis for functionalreplacement of an atrio-ventricular heart valve in a connection channel,having a circumferential connection channel wall structure, between theatrial chamber and the ventricular chamber of a heart, comprising: aradially expandable tubular body configured to be disposed in theinterior of the connection channel and extending along an axis, and avalve arranged within and attached to the tubular body, wherein thetubular body is provided with an outer circumferential groove which isopen to the radial outside of the tubular body and which defines agroove bottom, whereby the tubular body is separated by the outercircumferential groove into first and second body sections, and whereinthe tubular body is provided with a first plurality of projections whichextend from the first or second body section in an axial direction ofthe tubular body and each of which has a free end arranged to overlapthe outer circumferential groove, further comprising an elongate outermember to be disposed at the exterior of the connection channel wallstructure at a level of the circumferential grove, wherein the elongateouter member is configured to at least partially extend around thetubular body with valve tissue of the connection channel wall structurebeing correspondingly circumferentially arranged between the tubularbody and the outer member and in such a radial distance to the axis ofthe tubular body that the valve tissue of the connection channel wallstructure can be radially forced into the outer circumferential grooveso as to be at least partially located radially below the projections.2. The transcatheter atrio-ventricular valve prosthesis according toclaim 1, wherein the first body section is adapted to be arranged on aside of the atrial chamber in the connection channel and the second bodysection is adapted to be arranged on a side of the ventricular chamberin the connection channel, and wherein the first plurality ofprojections extends from the second body section.
 3. The transcatheteratrio-ventricular valve prosthesis according to claim 1, wherein theelongate outer member comprises a tubular structure having a centrallongitudinal axis so as to extend in the circumferential groove in acircumferential direction of the tubular body, wherein the elongateouter member has a cross-sectional diameter transverse to its centrallongitudinal axis and wherein the cross-sectional diameter is eitherlarger than 2 mm or smaller than 15 mm.
 4. The atrio-ventricular valveprosthesis according to claim 1, wherein the elongate outer membercomprises an inflatable member which is adapted to be inflated by asubstance so as to expand the elongate outer member.
 5. Thetranscatheter atrio-ventricular valve prosthesis according to claim 1,wherein the elongate outer member is configured to be expandable and/orcompressible in a radial direction of its cross-sectional diameter. 6.The atrioventricular valve prosthesis according to claim 4, wherein thesubstance is a curable substance that is adapted to be cured in theinflatable member so as to give the elongate outer member rigidity. 7.The atrio-ventricular valve prosthesis according to claim 1, wherein theelongate outer member extends partially around the tubular body at least180°, and has spaced and non-abutting free ends.
 8. Theatrio-ventricular valve prosthesis according to claim 1, wherein theelongate outer member is made from a mesh-type structure.
 9. Thetranscatheter atrio-ventricular valve prosthesis according to claim 1,wherein the tubular body comprises a mesh-type body having elongate meshelements crossing each other at crossings, wherein the plurality ofprojections is formed monolithically integrally with the tubular body.10. The transcatheter atrio-ventricular valve prosthesis according toclaim 1, wherein a diameter of the first body section in a radialdirection of the axis is larger than any diameter of the second bodysection in a radial direction of the axis.
 11. The transcatheteratrio-ventricular valve prosthesis according to claim 1, wherein thetubular body is provided with a first and a second plurality ofprojections which extend from the first and the second body sections,respectively, in opposite axial directions of the tubular body and eachof which has a free end arranged to overlap the outer circumferentialgroove.
 12. The transcatheter atrio-ventricular valve prosthesisaccording to claim 11, wherein at least one of the first and the secondplurality of projections is provided in a rectilinear shape.
 13. Thetranscatheter atrio-ventricular valve prosthesis according to claim 11,wherein the first and the plurality of projections extend from the firstand the second body sections, respectively, at a radial distance to thegroove bottom so as to define a hollow chamber between the projectionsand the groove bottom.
 14. The transcatheter atrio-ventricular valveprosthesis according to claim 11, wherein the first and the secondplurality of projections extend from the first and the second bodysections, respectively, at an area adjacent to the radial outercircumference of the outer circumferential groove.
 15. The transcatheteratrio-ventricular valve prosthesis according to claim 11, wherein thefirst and the second pluralities of projections extend at an angle (β)to the axis of the tubular body radially inwardly into the outercircumferential groove, wherein the angle (β) may be equal to or smallerthan 45°.
 16. The transcatheter atrio-ventricular valve prosthesisaccording to claim 11, wherein the first and the second pluralities ofprojections substantially extend in planes including the axis of thetubular body.
 17. The transcatheter atrio-ventricular valve prosthesisaccording to claim 11, wherein the free ends of the first and the secondpluralities of projections are either acute or sharpened ends.
 18. Thetranscatheter atrio-ventricular valve prosthesis according to claim 11,wherein the free ends of the first and the second pluralities ofprojections are provided with barbs or hooks.
 19. The transcatheteratrio-ventricular valve prosthesis according to claim 11, wherein thetubular body is a mesh type body having elongated mesh elements crossingeach other at crossings, and wherein the first and the secondpluralities of projections extend from crossings adjacent to the outercircumferential groove.
 20. The transcatheter atrio-ventricular valveprosthesis according to claim 1, wherein, when seen in an axial sectionalong the tubular body, the direction of a curvature or bend in theaxial profile between the groove and the first body section and/orbetween the groove (45) and the second body section changes from aconcave curvature of the groove to a convex curvature at the transitionbetween the groove and first and or second body section.
 21. Thetranscatheter atrio-ventricular valve prosthesis according to claim 1,wherein the elongate outer member comprises one or more clampingmembers, where each clamping member comprises a tubular clamping memberbody which extends along an axis in a circumferential direction of thetubular member and which is radially expandable with respect to the axisof the clamping member so as to force the tissue of the circumferentialconnection channel wall structure inwardly in radial direction of thetubular body into the outer circumferential groove.
 22. Thetranscatheter atrio-ventricular valve prosthesis according to claim 11,further comprising one or more clamping members configured to bedisposed within the circumferential groove radially below the firstand/or the second plurality of projections with valve tissue of theconnection channel wall structure between the first and/or secondplurality of projections and the respective clamping member, wherein therespective clamping member applies a radial clamping force against thegroove bottom and the valve tissue, so as to radially force the valvetissue towards the groove bottom.
 23. The transcatheteratrio-ventricular valve prosthesis according to claim 1, wherein thetranscatheter atrio-ventricular valve prosthesis is a sub-annularlyanchoring prosthesis adapted to be implanted with the circumferentialgroove being located on a side of a ventricular chamber of a valveannulus of the heart valve and the circumferential groove having adistance to the valve annulus.
 24. The transcatheter atrio-ventricularvalve prosthesis according to claim 1, wherein the elongate outer membercomprises an angularly shaped cross section with a first angular leg,extending with respect to the axis generally radially into thecircumferential groove, and a second angular leg extending generallyparallel to the axis of the tubular body on an outside of the tubularbody so as to be disposed between the second body section of the tubularbody and a ventricular chamber wall of the heart.
 25. Method forimplanting a transcatheter atrio-ventricular valve prosthesiscomprising: a tubular body having a longitudinal axis, a circumferentialgroove and a plurality of projections each having a free end arranged soas to partially overlap the groove, and an elongate outer member, themethod comprising the steps of: positioning the tubular body inside aconnection channel between an atrial and a ventricular chamber of aheart, positioning the elongate outer member on an outside of theconnection channel at an axial level of the circumferential groove, andfixating the prosthesis relative to the heart by reducing a distancebetween the elongate outer member and the tubular body so that tissue ofthe connection channel is inserted into the groove so as to at leastpartially be radially inside of the projections with respect to axis.26. Method for implanting a transcatheter atrio-ventricular valveprosthesis according to claim 25, further comprising positioning thetubular body such that the groove is positioned adjacent to the annulusof a native mitral valve towards the ventricular chamber, so that whenthe elongate outer member is inserted into the groove, a sub-annularprosthesis anchoring is achieved by the engagement of the elongate outermember in the groove.
 27. The method according to claim 25, wherein thestep of positioning the tubular body comprises entering the heart cavityusing an arterial retrograde approach and/or using a venous access and apuncture through the inter-atrial septum and/or using a trans-apicalapproach by puncturing through the apex of the heart and or puncturingan atrial wall from an outside of the heart and or using anfemoral-arterial access through a puncture in the groin.
 28. The methodaccording to claim 25, wherein the elongate outer member comprises across-sectional diameter and wherein the step of fixating the prosthesiscomprises changing the cross-sectional diameter of the elongate outermember so as to reduce the radial distance between the elongate outermember and the tubular body.
 29. The method according to claim 28,wherein the elongate outer member comprises an inflatable member andwherein changing the cross-sectional diameter of the elongate outermember comprises inflating the inflatable member.
 30. The methodaccording to claim 29, wherein inflating is achieved by infilling acurable substance into the inflatable member, and wherein the curablesubstance is cured in an inflated condition of the inflatable member.31. The method according to claim 25, wherein the prosthesis comprises aplurality of projections, and wherein the step of fixating theprosthesis comprises (i) placing the elongate outer member at leastpartially radially inwards of the projections with respect to axis, and(ii) comprises piercing the elongate outer member with the plurality ofprojections, so that the elongate outer member is held by the pluralityof projections.
 32. A system for implanting a heart valve, comprising: aradially self-expandable tubular body having an inflow end and anoutflow end and a preformed groove disposed at an outer surface of thetubular body between the inflow end and the outflow end, the preformedgroove extending at least partially around the tubular body and having acircumferential opening facing radially outward of the tubular body; avalve disposed within and attached to the tubular body; and an elongateouter member configured to form a loop encircling the preformed groove,wherein the outflow end of the tubular body includes a funnel shape thattapers inward toward a center of the tubular body such that a diameterof the outflow end is less than a maximum diameter of the tubular bodywhen the tubular body is fully deployed within the patient.
 33. Thesystem according to claim 32, further including a trapping memberconfigured to be moved into the preformed groove to form at least apartial loop around the tubular body.
 34. A method for implanting areplacement valve in patient's heart, comprising: advancing an elongateouter member from a first delivery catheter to form a loop aroundportions of native valve leaflets and/or chordae with the elongate outermember; deploying from a second delivery catheter a radiallyself-expandable tubular body having an inflow end and an outflow end, avalve disposed within a lumen of the tubular body, and a preformedgroove disposed at an outer surface of the tubular body between theinflow end and the outflow end, the preformed groove extending at leastpartially around the tubular body and having a circumferential openingfacing radially outward of the tubular body, such that, when the tubularbody is deployed, the outflow end of the tubular body includes a funnelshape that tapers inward toward an axis of the tubular body and adiameter of the outflow end is less than a maximum diameter of thetubular body; and moving the loop into the preformed groove through theopening.
 35. The method according to claim 34, further includingtrapping the portions of the native valve leaflets and/or chordae withinthe preformed groove with a trapping member.
 36. The method according toclaim 34, wherein at least one of the inflow end and the outflow end hasa non-circular cross-section.
 37. The method according to claim 36,wherein the at least one of the inflow end and the outflow end has anoval-shaped or a D-shaped cross-section.
 38. The method according toclaim 37, wherein the cross-section has a major axis and a minor axis,and the minor axis is arranged in the septo-lateral direction.
 39. Themethod according to claim 34, wherein the portions of native valveleaflets and/or chordae form a portion of a mitral valve or a tricuspidvalve.
 40. A system for implanting a heart valve, comprising: a radiallyself-expandable tubular body having an inflow end, an outflow end, and apreformed groove (a) disposed in outer surface of the tubular bodybetween the inflow end and the outflow end, (b) extending at leastpartially around the tubular body, and (c) having a circumferentialopening facially radially outward of the tubular body; a valve disposedwithin and attached to the tubular body; and a trapping memberconfigured to form at least a partial loop around the preformed groovewhen the tubular body is fully expanded, wherein the inflow end of thetubular body is self-expandable to a shape that constrains movement ofthe tubular body in an outflow direction by contact in a flow directionbetween the inflow end of the tubular body and an annulus of a nativeheart valve when the tubular body is deployed within a heart and alignedwith the native heart valve, and the trapping member is configured toextend around portions of chordae and/or leaflets of the native heartvalve within the groove when the tubular body is deployed within thepatient and aligned with the native heart valve, and constrain movementof the tubular body in a direction opposite the flow direction.
 41. Thesystem according to claim 40, wherein the tubular body is a stent. 42.The system according to claim 40, wherein the trapping member includes apartial loop.
 43. The system according to claim 40, wherein the trappingmember includes a closed loop.
 44. The system according to claim 40,wherein the trapping member and the tubular body are configured to leavea radial gap between (a) at least one of the trapping member and thetubular body and (b) chordae or valve leaflets, when the trapping memberis deployed around portions of chordae and leaflets of the native valvewithin the groove and the tubular body is fully expanded.
 45. The systemaccording to claim 40, wherein the trapping member is not configured toapply a radial force inward when deployed.
 46. The system according toclaim 40, further comprising a projection having a first end located ata side surface of the tubular body and a second free end, the groovedefined between the projection and the side surface of the tubular body.47. The system according to claim 40, wherein an outer diameter of theinflow end is greater than an outer diameter of the outflow end.
 48. Amethod for implanting a replacement valve in a patient's heart,comprising: deploying at least a partial loop around portions of chordaeand/or leaflets of a native heart valve at a downstream portion of thenative heart valve such that movement of the loop in an upstreamdirection relative to an annulus of the native heart valve is limited bythe portions of chordae and/or leaflets; deploying a radiallyself-expandable tubular body, having (a) a valve disposed within a lumenof the tubular body and (b) a preformed groove located at an outersurface of the tubular body between an inflow end and an outflow end ofthe tubular body and having a circumferential opening facing radiallyoutward of the tubular body, within the at least partial loop such thatthe at least partial loop and portions of the chordae and/or leafletsare located at least partially within the groove and movement of thetubular body relative to the at least partial loop in an upstreamdirection is limited; and allowing an inflow end portion of the tubularbody to expand beyond the annulus of the native heart valve upstream ofthe native heart valve so that downstream movement of the tubular bodythrough the native heart valve is limited.
 49. The method according toclaim 48, wherein the native heart valve is a mitral valve, andexpansion of the inflow end portion of the tubular body prevents thetubular body from moving out of alignment with the native heart valveand toward the patient's ventricle apex.
 50. The method according toclaim 49, wherein interaction between the at least the partial loop, thegroove, and the chordae and/or leaflets prevents the tubular body frommoving out of alignment with the native heart valve and toward thepatient's atrium.
 51. The method according to claim 48, wherein the atleast partial loop is formed by passing an elongate outer member aroundthe chordae and/or leaflets, and moving a trapping member along theelongate outer member to form the at least partial loop.
 52. The methodaccording to claim 48, wherein the at least partial loop is formedaround portions of both the chordae and the leaflets.
 53. The methodaccording to claim 48, further comprising leaving a radial gap betweenthe at least partial loop and the tubular body.
 54. The method accordingto claim 48, wherein the loop is a closed loop.